Does the effectiveness of IUI in couples with unexplained subfertility depend on their prognosis of natural conception? A replication of the H2Oil study

Study question Can we replicate the finding that the benefit of IUI-ovarian stimulation (IUI-OS) compared to expectant management for couples with unexplained subfertility depends on the prognosis of natural conception?Summary answer The estimated benefit of IUI-OS did not depend on the prognosis of natural conception but did depend on when treatment was started after diagnosis, with starting IUI-OS later yielding a larger absolute and relative benefit of treatment.What is known already IUI-OS is often the first-line treatment for couples with unexplained subfertility. Two randomized controlled trials (RCTs) compared IUI-OS to expectant management using different thresholds for the prognosis of natural conception as inclusion criteria and found different results. In a previous study (a Dutch national cohort), it was found that the benefit of IUI-OS compared to expectant management seemed dependent on the prognosis of natural conception, but this finding warrants replication. Study design size durationWe conducted a secondary analysis of the H2Oil study (n = 1119), a multicentre RCT that evaluated the effect of oil-based contrast versus water-based contrast during hysterosalpingography (HSG). Couples were randomized before HSG and followed up for 3-5 years. We selected couples with unexplained subfertility who received HSG and had follow-up or pregnancy data available. Follow-up was censored at the start of IVF, after the last IUI cycle or at last contact and was truncated at a maximum of 18 months after the fertility workup.Participants/materials setting methodsThe endpoint was time to conception leading to an ongoing pregnancy. We used the sequential Cox approach comparing in each month the ongoing pregnancy rates over the next 6 months of couples who started IUI-OS to couples who did not. We calculated the prognosis of natural conception for individual couples, updated this over consecutive failed cycles and evaluated whether prognosis modified the effect of starting IUI-OS. We corrected for known predictors of conception using inverse probability weighting.Main results and the role of chanceData from 975 couples were available. There were 587 couples who received at least one IUI-OS cycle within 18 months after HSG of whom 221 conceived leading to an ongoing pregnancy (rate: 0.74 per couple per year over a median follow-up for IUI of 5 months). The median period between HSG and starting IUI-OS was 4 months. Out of 388 untreated couples, 299 conceived naturally (rate: 0.56 per couple per year over a median follow-up of 4 months). After creating our mimicked trial datasets, starting IUI-OS was associated with a higher chance of ongoing pregnancy by a pooled, overall hazard ratio of 1.50 (95% CI: 1.19-1.89) compared to expectant management. We did not find strong evidence that the effect of treatment was modified by a couple's prognosis of achieving natural conception (Akaike's Information Criterion (AIC) decreased by 1 point). The effect of treatment was dependent on when couples started IUI-OS (AIC decreased by more than 2 points). The patterns of estimated absolute chances over time for couples with increasingly better prognoses were different from the previous study but the finding that starting later yields a larger benefit of treatment was similar. We found IUI-OS increased the absolute chance of pregnancy by at least 5% compared to expectant management. The absolute chance of pregnancy after IUI-OS seems less variable between couples and starting times of treatment than the absolute chance after expectant management.Limitations reasons for cautionThis is a secondary analysis, as the H2Oil trial was not designed with this research question in mind. Owing to sample size restrictions, it remained difficult to distinguish between the ranges of prognoses in which true benefit was found.Wider implications of the findingsWe replicated the finding that starting IUI-OS later after diagnosis yields a larger absolute and relative benefit of treatment. We did not replicate the dependency of the effect of IUI-OS on the prognosis of natural conception and could not identify clear thresholds for the prognosis of natural conception when IUI-OS was and/or was not effective. Because many of these couples still have good chances of natural conception at the time of diagnosis, we suggest clinicians should advise couples to delay the start of IUI-OS for several months to avoid unnecessary treatment. Study funding/competing interestsThe H2Oil study (NTR 3270) was an investigator-initiated study that was funded by the two academic institutions (AMC and VUmc) of the Amsterdam UMC. The follow-up study (NTR 6577) was also an investigator-initiated study with funding by Guerbet, France. The funders had no role in study design, collection, analysis and interpretation of the data. B.W.M. is supported by an Investigator grant (GNT1176437) from the Australian National Health and Medical Research Council (NHMRC). K.D. reports receiving travel and speaker fees from Guerbet. B.W.M. reports consultancy for ObsEva, Merck, Merck KGaA, iGenomix and Guerbet. V.M. reports receiving travel- and speaker fees as well as research grants from Guerbet.R. van Eekelen, K. Rosielle, N. van Welie, K. Dreyer, M. van Wely, M. van Wely ... et al

Consistency and diversity of spike dynamics in the neurons of bed nucleus of Stria Terminalis of the rat: a dynamic clamp study

Neurons display a high degree of variability and diversity in the expression and regulation of their voltage-dependent ionic channels. Under low level of synaptic background a number of physiologically distinct cell types can be identified in most brain areas that display different responses to standard forms of intracellular current stimulation. Nevertheless, it is not well understood how biophysically different neurons process synaptic inputs in natural conditions, i.e., when experiencing intense synaptic bombardment in vivo. While distinct cell types might process synaptic inputs into different patterns of action potentials representing specific "motifs'' of network activity, standard methods of electrophysiology are not well suited to resolve such questions. In the current paper we performed dynamic clamp experiments with simulated synaptic inputs that were presented to three types of neurons in the juxtacapsular bed nucleus of stria terminalis (jcBNST) of the rat. Our analysis on the temporal structure of firing showed that the three types of jcBNST neurons did not produce qualitatively different spike responses under identical patterns of input. However, we observed consistent, cell type dependent variations in the fine structure of firing, at the level of single spikes. At the millisecond resolution structure of firing we found high degree of diversity across the entire spectrum of neurons irrespective of their type. Additionally, we identified a new cell type with intrinsic oscillatory properties that produced a rhythmic and regular firing under synaptic stimulation that distinguishes it from the previously described jcBNST cell types. Our findings suggest a sophisticated, cell type dependent regulation of spike dynamics of neurons when experiencing a complex synaptic background. The high degree of their dynamical diversity has implications to their cooperative dynamics and synchronization

Treatment effect of oil-based contrast is related to experienced pain at HSG : a post-hoc analysis of the randomised H2Oil study

The H2Oil study was an investigator-initiated study that was funded by our own academic institutions (AMC and VUmc) of the Amsterdam UMC. The funders had no role in study design, collection, analysis and interpretation of the data.Peer reviewedPublisher PD

Exploring the similarities and differences between medical assessments of competence and criminal responsibility

The medical assessments of criminal responsibility and competence to consent to treatment are performed, developed and debated in distinct domains. In this paper I try to connect these domains by exploring the similarities and differences between both assessments. In my view, in both assessments a decision-making process is evaluated in relation to the possible influence of a mental disorder on this process. I will argue that, in spite of the relevance of the differences, both practices could benefit from the recognition of this similarity. For cooperative research could be developed directed at elucidating exactly how various mental disturbances can affect decision-making processes

Mechanisms explaining transitions between tonic and phasic firing in neuronal populations as predicted by a low dimensional firing rate model

Several firing patterns experimentally observed in neural populations have been successfully correlated to animal behavior. Population bursting, hereby regarded as a period of high firing rate followed by a period of quiescence, is typically observed in groups of neurons during behavior. Biophysical membrane-potential models of single cell bursting involve at least three equations. Extending such models to study the collective behavior of neural populations involves thousands of equations and can be very expensive computationally. For this reason, low dimensional population models that capture biophysical aspects of networks are needed. \noindent The present paper uses a firing-rate model to study mechanisms that trigger and stop transitions between tonic and phasic population firing. These mechanisms are captured through a two-dimensional system, which can potentially be extended to include interactions between different areas of the nervous system with a small number of equations. The typical behavior of midbrain dopaminergic neurons in the rodent is used as an example to illustrate and interpret our results. \noindent The model presented here can be used as a building block to study interactions between networks of neurons. This theoretical approach may help contextualize and understand the factors involved in regulating burst firing in populations and how it may modulate distinct aspects of behavior.Comment: 25 pages (including references and appendices); 12 figures uploaded as separate file

A process model for developing learning design patterns with international scope

This paper investigates the process of identifying design patterns in international collaborative learning environments. In this context, design patterns are referred to as structured descriptions of best practice with pre-defined sections such as problem, solution and consequences. We pay special attention to how the scope of a design pattern is identified and articulated. Based on a review of the seminal design patterns literature and current practice in the area of learning design, the lack of a more specific process description for developing patterns with international scope is identified. The paper suggests a process model for developing patterns with international scope. This model is exemplified in a case study that links the analysis of observation in international learning environments to the articulation of design patterns by identifying culturally independent core values that constitute the foundations of a design pattern with international scope. These core values are linked to recurrent learning behaviors and specific artefacts that support learning in the articulation of a design pattern. The findings contribute to gaining a deeper understanding of the pattern scoping and abstraction process in international learning environments

Homeostatic Scaling of Excitability in Recurrent Neural Networks

Neurons adjust their intrinsic excitability when experiencing a persistent change in synaptic drive. This process can prevent neural activity from moving into either a quiescent state or a saturated state in the face of ongoing plasticity, and is thought to promote stability of the network in which neurons reside. However, most neurons are embedded in recurrent networks, which require a delicate balance between excitation and inhibition to maintain network stability. This balance could be disrupted when neurons independently adjust their intrinsic excitability. Here, we study the functioning of activity-dependent homeostatic scaling of intrinsic excitability (HSE) in a recurrent neural network. Using both simulations of a recurrent network consisting of excitatory and inhibitory neurons that implement HSE, and a mean-field description of adapting excitatory and inhibitory populations, we show that the stability of such adapting networks critically depends on the relationship between the adaptation time scales of both neuron populations. In a stable adapting network, HSE can keep all neurons functioning within their dynamic range, while the network is undergoing several (patho)physiologically relevant types of plasticity, such as persistent changes in external drive, changes in connection strengths, or the loss of inhibitory cells from the network. However, HSE cannot prevent the unstable network dynamics that result when, due to such plasticity, recurrent excitation in the network becomes too strong compared to feedback inhibition. This suggests that keeping a neural network in a stable and functional state requires the coordination of distinct homeostatic mechanisms that operate not only by adjusting neural excitability, but also by controlling network connectivity

Free will and psychiatric assessment of criminal responsibility. A parallel with informed consent

In some criminal cases a forensic psychiatrist is asked to make an assessment of the state of mind of the defendant at the time of the legally relevant act. A considerable number of people seem to hold that the basis for this assessment is that free will is required for legal responsibility, and that mental disorders can compromise free will. In fact, because of the alleged relationship between the forensic assessment and free will, researchers in forensic psychiatry also consider the complicated metaphysical discussions on free will relevant to the assessment. At the same time, there is concern about the lack of advancement with respect to clarifying the nature of the forensic assessment. In this paper I argue that, even if free will is considered relevant, there may be no need for forensic researchers to engage into metaphysical discussions on free will in order to make significant progress. I will do so, drawing a parallel between the assessment of criminal responsibility on the one hand, and the medical practice of obtaining informed consent on the other. I argue that also with respect to informed consent, free will is considered relevant, or even crucial. This is the parallel. Yet, researchers on informed consent have not entered into metaphysical debates on free will. Meanwhile, research on informed consent has made significant progress. Based on the parallel with respect to free will, and the differences with respect to research, I conclude that researchers on forensic assessment may not have to engage into metaphysical discussions on free will in order to advance our understanding of this psychiatric practice. © 2010 The Author(s)

Ih-mediated depolarization enhances the temporal precision of neuronal integration

Feed-forward inhibition mediated by ionotropic GABAA receptors contributes to the temporal precision of neuronal signal integration. These receptors exert their inhibitory effect by shunting excitatory currents and by hyperpolarizing neurons. The relative roles of these mechanisms in neuronal computations are, however, incompletely understood. In this study, we show that by depolarizing the resting membrane potential relative to the reversal potential for GABAA receptors, the hyperpolarization-activated mixed cation current (Ih) maintains a voltage gradient for fast synaptic inhibition in hippocampal pyramidal cells. Pharmacological or genetic ablation of Ih broadens the depolarizing phase of afferent synaptic waveforms by hyperpolarizing the resting membrane potential. This increases the integration time window for action potential generation. These results indicate that the hyperpolarizing component of GABAA receptor-mediated inhibition has an important role in maintaining the temporal fidelity of coincidence detection and suggest a previously unrecognized mechanism by which Ih modulates information processing in the hippocampus